1. Field
This application relates generally to the operation of communication systems, and more particularly, to a system, method, and computer readable media for measuring a rise-over-thermal characteristic in a communication network.
2. Background Information
Wireless communication networks are currently in widespread use to allow mobile station users to wirelessly communicate with each other and other network entities. In one type of network, multiple stations in a particular geographic region may simultaneously communicate with a hub or base station using the same frequency band. This type of network is referred to as a self-interfering network. A code division multiple access (CDMA) network is an example of a self-interfering network. Thus, the total signal power received by the base station in that frequency band may represent simultaneous transmissions from a number of the stations in the region.
It has become increasingly important for wireless communication networks to provide both data and voice services. Providing data services results in a significant increase in traffic between mobile stations and their associated base stations. For optimal network performance, especially in self-interfering networks, the transmission power of the mobile stations is carefully controlled. It can be seen that a change in transmit power by one station may affect the operation of other mobile stations, for example, requiring them to likewise change their power. In some cases, a network limit may be exceeded if a large number of mobile stations respond to one another by respectively increasing their power. This may cause the network to become unstable. To avoid this from happening, the network load may be balanced, for example, by controlling the transmission power of each mobile station to minimize its impact on other mobile stations and to accommodate for noise power in the network. The noise power is based on environmental factors, such as temperature, which change throughout the day. Thus, any technique that attempts to adjust the network load needs to account for changing noise power in the network.
One technique that is used to adjust the load of a network measures a network characteristic referred to as the rise-over-thermal (RoT). The RoT is a ratio between the total power in the reverse link (Pr) and the thermal noise power (N) that is received at a receiver (i.e., base station). Adjusting the transmission power of the stations to achieve a selected RoT characteristic is one way to balance the network load, and thereby optimize the performance of the network. However, because the noise power changes throughout the day due to environmental factors, the RoT characteristic of the network also changes. Thus, to maintain a selected RoT characteristic, the noise power in the network needs to be measured throughout the day and the transmission power of the stations adjusted accordingly. For example, as the noise power in the network increases, the RoT characteristic changes indicating that the signal power of one or more stations may need to be adjusted to return to the desired RoT characteristic. Thus, obtaining an accurate noise power measurement, and corresponding RoT measurement, is important to optimize the network and thereby provide data and voice services in the most efficient manner.
Unfortunately, conventional techniques that are used to measure RoT characteristics in communication networks have several drawbacks. For example, one technique operates to measure the noise power by disabling transmissions from all the mobile stations communicating with a particular base station, so that the noise power received at the base station can be measured. However, this technique requires interruptions to network services because transmissions from those mobile stations have to be suspended. Furthermore, these interruptions may have to be repeated several times per day in order to get accurate RoT measurements as the noise power in the network changes. Consequently, even if such a technique is utilized in a way that doesn't occur very often and the duration of the silence interval is limited, there may be no standard provisions to enable this silence period in conventional systems, and changing the existing communication standards to allow it may not be backward compatible.
Therefore, what is needed is a system to accurately measure RoT characteristics in a communication network so that the network load may be optimized. Unlike conventional technology, the system should operate to accurately measure RoT characteristics as needed throughout the day without significantly impacting normal network communications while maintaining backward compatibility with existing network standards.